2508.10.00.00 - Bentonite

This HTS classification covers bentonite, a naturally occurring clay primarily composed of montmorillonite. Bentonite is characterized by its exceptional swelling capacity and ability to form gels when mixed with water, properties that stem from its unique layered silicate structure. It finds widespread industrial applications as an absorbent, a binder, a clarifying agent, and a rheological modifier in various sectors, including drilling fluids, foundry molds, animal feed, and cosmetics.

While the parent heading 2508 encompasses several types of clays and related minerals, bentonite is specifically distinguished from its siblings. Fire-clay (2508.30.00.00), for instance, is a refractory clay characterized by its high alumina and silica content and resistance to high temperatures, typically used in ceramics and refractories. Other clays within heading 2508 (2508.40.01) are more general classifications for clays not otherwise specified. Andalusite, kyanite, and sillimanite (2508.50.00.00) are aluminosilicate minerals with specific industrial uses due to their high refractoriness. Mullite (2508.60.00.00) is a synthetic ceramic material, and chamotte or dinas earth (2508.70.00.00) are calcined refractory clays. Bentonite's unique swelling and thixotropic properties are its primary differentiating factors from these related mineral products.

As a leaf node, HTS code 2508.10.00.00 does not have further subdivisions. Classification within this code is based on the material's identity as bentonite, irrespective of its processing (e.g., drying, grinding) or origin, as long as it retains its essential characteristics. Trade descriptions, geological origin, or specific purities are generally not defining factors for this classification, provided the material meets the chemical and physical criteria for bentonite.